In general a rotary plow feeder includes a bin, hopper or other container for bulk granular material having a bottom wall provided with a feed aperture through which granular material is fed by a rotary plow device located above the aperture and close to the bottom wall. Rotation of the plow device about the vertical axis of the aperture results in the urging of granular material toward the aperture and over the edge of the aperture to fall by gravity from the container.
Examples of prior art rotary plow feeders are described in U.S. Pat. Nos. 217,628, 243,716, 371,881, 1,856,361, 3,036,745 and 4,020,980.
An example of a more recently developed rotary plow feeder is described in U.S. patent application Ser. No. 291,765 of which the present application is a continuation-in-part. The feeder described in that application, the disclosure of which is incorporated herein by reference, employs a specially shaped plow blade or scoop which provides particularly efficient flow of granular material uniformly and simultaneously over essentially the whole of the periphery of the feed aperture during rotation of the blade.